Calcium hydroxide inactivates lipoteichoic acid from Enterococcus faecalis.
Calcium hydroxide is a widely used endodontic medicament for eliminating viable bacteria and inactivating virulence factors. Enterococcus faecalis, a pathogenic gram-positive bacterium, has been associated with refractory apical periodontitis. Because lipoteichoic acid (LTA) is a major virulence factor of gram-positive bacteria, we examined whether calcium hydroxide could detoxify LTA from E. faecalis. An enzyme-linked immunosorbent assay showed that calcium hydroxide-killed E. faecalis was less potent than heat-killed bacteria in stimulating the release of tumor necrosis factor-alpha by a murine macrophage line, RAW 264.7 (P < 0.05). Pretreatment of LTA with calcium hydroxide remarkably abrogated the ability of LTA to induce the release of tumor necrosis factor-alpha (P < 0.05). Furthermore, calcium hydroxide-treated LTA was not able to stimulate Toll-like receptor 2, which recognizes functionally intact LTA. These results suggest that calcium hydroxide could detoxify LTA, resulting in attenuation of the inflammatory responses to E. faecalis and its LTA.
Baik
Jung Eun
JE
Department of Oral Microbiology and Immunology, Dental Research Institute, and BK21 Program, School of Dentistry, Seoul National University.
Kum
Kee-Yeon
KY
Department of Conservative Dentistry and Dental Research Institute, School of Dentistry, Seoul National University.
Yun
Cheol-Heui
CH
School of Agricultural Biotechnology, Seoul National University; Research Institute for Agriculture and Life Sciences, Seoul National University.
Lee
Jin-Kyung
JK
Department of Conservative Dentistry and Dental Research Institute, School of Dentistry, Seoul National University.
Lee
Kangseok
K
Department of Life Science, Chung-Ang University.
Kim
Kack Kyun
KK
Department of Oral Microbiology and Immunology, Dental Research Institute, and BK21 Program, School of Dentistry, Seoul National University.
Han
Seung Hyun
SH
Department of Oral Microbiology and Immunology, Dental Research Institute, and BK21 Program, School of Dentistry, Seoul National University; International Vaccine Institute, Seoul, Republic of Korea. Electronic address: shhan-mi@snu.ac.kr.
D000818:Animals; D002126:Calcium Hydroxide / Q000494:pharmacology*; D002460:Cell Line; D013293:Enterococcus faecalis / Q000737:chemistry / Q000187:drug effects*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors*; D008262:Macrophage Activation / Q000187:drug effects*; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D012388:Root Canal Irrigants / Q000494:pharmacology*; D013682:Teichoic Acids / Q000037:antagonists & inhibitors*; D051195:Toll-Like Receptor 2 / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D037521:Virulence Factors / Q000037:antagonists & inhibitors
D008070:Lipopolysaccharides; D016328:NF-kappa B; D012388:Root Canal Irrigants; D013682:Teichoic Acids; D051195:Toll-Like Receptor 2; D014409:Tumor Necrosis Factor-alpha; D037521:Virulence Factors; C009900:lipoteichoic acid; D002126:Calcium Hydroxide